No. Venturi-generated vacuum is fine for sample drying in chemistry lab but is incapable of generating the > 29" Hg vacuum necessary for A/C system evacuation.

The Harbor Freight tool vacuum level is listed at 28.3" Hg, requires two minutes to reach that level internally (before being connected to an A/C system) and uses 4.2 cf of air per minute. An air compressor of appropriate capacity is necessary just to power this.... and lower air flows will result in even poorer evacuation. Regardless of the length of time run, this venturi pump is incapable of reaching the level of evacuation needed.

Invest in a proper vacuum pump... it will pay for itself in the long run. And buy several spare quarts of pump oil... rotary vane pump efficiency falls off as the oil absorbs water vapor and debris scavaged from the system.